The Lotus Cars Community banner
1 - 16 of 16 Posts

·
Banned
Joined
·
338 Posts
Discussion Starter · #1 ·
There has been a lot of talk that the Elise needs more power so maybe slap on a turbo or supercharger, however then there is that dreaded turbo lag.
What about dropping in an engine that is higher in hp but also lighter in weight, which is also not FI either so no lag???
I am thinking of a sport bike engine like the Suzuki Hayabusa engine, modified to put out about 250 hp, like the one in the Radical SR3 that I drove at the track. Wouldn't that engine be lighter than the Toyota, and why not also throw in the sequential 6 speed gear shifter for faster shifts. With this package I think it would be a killer Elise. Lighter and more powerful, can't beat that.
Cheers.
 

·
Registered
Joined
·
866 Posts
Actually this is a good question. i know that the gearing would be different and all of that, but theoretically, why are the specific outputs of motorcycle engines so much higher than car engines? How can 500cc engines put out 75 hp? Can someone please explain this to me....:cool:
 

·
Registered
Joined
·
136 Posts
It's been done :)

A Hayabusa engine (I believe) was dropped in to an S1 Elise. I'm not entirely sure that the car ever moved but it was created by Geary of http://www.eliseparts.com.

Another company over here http://www.lotusrepairs.com are currently dropping a 2.0l V8 in to an Elise which was created from joining a couple of R1 engines together and tidying them up a bit (ok, it's a bit more complex and that but that's the gist of it). There's one currently in a Caterham putting out around 340bhp with a potential 400bhp available. The engine weighs 73kg. Watch this space, power fans.

For reference, watch this: http://www.despistada.co.uk/rst/rst-v8-sprint.wmv

340bhp in 500kg from the engine mentioned above. The guy driving it is an ex-F1 test driver (he taught me to drive, too!) and even he didn't dare to use full throttle. A bit too hairy? :)
 

·
Registered
Joined
·
136 Posts
Mean TT said:
Actually this is a good question. i know that the gearing would be different and all of that, but theoretically, why are the specific outputs of motorcycle engines so much higher than car engines? How can 500cc engines put out 75 hp? Can someone please explain this to me....:cool:
You don't find many bike engines getting to 135,000 miles, to be fair :)
 

·
Registered
Joined
·
6,802 Posts
I'd suspect you'd have a huge power loss driving a rear axle two wheels combined with the increased weight (believe the elise is substantially heavier than a radical, certainly heavier than a busa).

Don't know the longevity of the engine either. So guess we're not talking about a street car.

Chris
 

·
Registered
Joined
·
1,078 Posts
You see absurd power levels out of modern bike engines because they can rev.
If you want a bike engine in a car as heavy as the Elise you want to look at the amount of torque the bike engine puts out, and importantly, how low in the rev band the torque is produced.
Torque is what makes cars drivable, Horsepower is for bar chat.
Horsepower is the ability to make torque, but if the lump is making 200hp at 13000rpm then the best torque figure will be way up high as well.
You'll need more revs to launch a BEE from a standstill due to the weight. This is hard on the clutch(a small unit also) plus the weight makes the engine lug at lower revs which is not good for its longevity.
The Bike engines do better in BECs like the sevens as these machines are easily stripped down, have live axled rear ends and none of the frou- frou weight enhancers on the Elise. They weigh about 800-1000 pounds which is less than half the weight of a complete basic spec Elise.
The car would be lighter with a bike engine in it but you'll be pulling the engine more frequently.

However... the V8 of 3.0 litres or less with 300+ hp based on two bike heads are coming soon...These should have sufficient low end twist to be docile in town.
m
 

·
Banned
Joined
·
338 Posts
Discussion Starter · #7 ·
S2000 -240hp engine

I assume that the Honda S2000 with the 240hp would not fit into the Elise, or it must be too heavy and thus effect the handling or else someone would have tried it.
It's too bad because that would have been one very quick car.
Cheers.
P.s. I read an article that initially Lotus tried to get a Honda engine for the Elise but that was a no go from Honda so they next went to Toyota.
 

·
Registered
Joined
·
4,985 Posts
Re: S2000 -240hp engine

Maverick1 said:
I assume that the Honda S2000 with the 240hp would not fit into the Elise, or it must be too heavy and thus effect the handling or else someone would have tried it.
It's too bad because that would have been one very quick car.
Cheers.
P.s. I read an article that initially Lotus tried to get a Honda engine for the Elise but that was a no go from Honda so they next went to Toyota.
The problem is that unless you want to do some massive re-engineering, the F20C won't work as the Elise layout needs a donor engine and transaxle from a FWD car.

I think the problem with the Hayabusa conversion is that it will only exacerbate the percieved problem of lack of low end torque. You'd be replacing a peaky, high revving motor with a peaker, higher revving motor. If it can be said that the Elise needs anything, it's not top end power but rather low-end grunt.
 

·
Registered
Joined
·
2,564 Posts
Re: S2000 -240hp engine

Maverick1 said:
I assume that the Honda S2000 with the 240hp would not fit into the Elise, or it must be too heavy and thus effect the handling or else someone would have tried it.
It's too bad because that would have been one very quick car.
Cheers.
P.s. I read an article that initially Lotus tried to get a Honda engine for the Elise but that was a no go from Honda so they next went to Toyota.
maybe you have not yet seen the K20 motor swaps?

www.prototyperacing.com

several other places in Europe do it as well.

The Honda motor is heavier, but is better than the Toyota motor & has more power. If someone were to be serious about it, you'd need to rework the suspension at the same time you do the swap.
 

·
Registered
Joined
·
788 Posts
Sounds like a lot of guys in the UK have the Honda engine installed in the S1 and love it. It's now becoming available in the S2 which is great.

One word though, if you read the Seloc site Prototype racing has a lot of very unhappy customers, so if you want to go down that route, be cautious. Very cautious.

This is secondhand opinion and I will stand corrected, but I think people should have advanced knowledge just in case.

Cheers
 

·
Registered
Joined
·
7,726 Posts
the busa engine is a fantastic motorcycle engine....keep it that way.
i mean if u wanna swap engines so bad use another car engine...unless u have a ton of money and just want bragging rights on doing a busa conversion on an elise....
not worth it.
 

·
Registered
Joined
·
495 Posts
thegit said:
You see absurd power levels out of modern bike engines because they can rev.
If you want a bike engine in a car as heavy as the Elise you want to look at the amount of torque the bike engine puts out, and importantly, how low in the rev band the torque is produced.
Torque is what makes cars drivable, Horsepower is for bar chat.
Horsepower is the ability to make torque, but if the lump is making 200hp at 13000rpm then the best torque figure will be way up high as well.
You'll need more revs to launch a BEE from a standstill due to the weight. This is hard on the clutch(a small unit also) plus the weight makes the engine lug at lower revs which is not good for its longevity.
The Bike engines do better in BECs like the sevens as these machines are easily stripped down, have live axled rear ends and none of the frou- frou weight enhancers on the Elise. They weigh about 800-1000 pounds which is less than half the weight of a complete basic spec Elise.
The car would be lighter with a bike engine in it but you'll be pulling the engine more frequently.

However... the V8 of 3.0 litres or less with 300+ hp based on two bike heads are coming soon...These should have sufficient low end twist to be docile in town.
m
You're forgetting one thing - gearing. You can't change hp by gearing but you can change torque. Gearing acts as a torque multiplier - I would rather have a high hp low torque engine (high rpm) than the other way around i.e. a diesel. Because I can compensate for the lack of torque by gearing. Yes you have to ring it's neck but it's a sports car and if you can't be bothered changing gear you shouldn't be driving it.
 

·
Registered
Joined
·
645 Posts
Who wants to make a custom transmission? Also, you'll either need 50 gears or settle for a top speed of about 35 if you are talking about gearing for a bike engine in a car around town.
 

·
Banned
Joined
·
6,941 Posts
>>>Yes you have to ring it's neck but it's a sports car and if you can't be bothered changing gear you shouldn't be driving it.<<<

People feel differently about this issue. One guy who is turbocharging his Elise wants to be able to avoid downshifting from 6th gear when he wants to pass folks rapidly...
--------------------------------------------------------------------------
I'll see if I can find any figures for the high-revving Elise, but for Vettes some reports showed:

6th gear acceleration, ZO6 / C6

30-50 MPH: 9.0 / 9.8

50-70 MPH: 8.6 / 9.0

50-75 MPH 11.6

Sorta looks like the torquey Vettes need a downshift from 6th to pass folks rapidly.
 

·
Registered
Joined
·
495 Posts
KuroiSport said:
Who wants to make a custom transmission? Also, you'll either need 50 gears or settle for a top speed of about 35 if you are talking about gearing for a bike engine in a car around town.
Not true - if you have a redline of say 10,000rpm you're in gear for longer. A 10K in the Elise would raise max speed in each gear by 10/15%. So you could reduce the gearing by the same amount and effectively increase the torque at the wheels. We're not talking about using a scooter engine - so no need for 50 gears. The important thing is optimize the ratio's. No point in gearing an engine for 200mph if it hasn't got the power to get you there. The Elise should be geared so that 6th will make V-Max at the redline and then work your way backwards.

People feel differently about this issue. One guy who is turbocharging his Elise wants to be able to avoid downshifting from 6th gear when he wants to pass folks rapidly...
Why??? What's so difficult about placing your foot on the clutch and selecting 5th. Using the gearbox is half the fun in owning a sports car.

Using a light pressure turbo will work as will supercharging. I'm surprised no one has mentioned individual throttle bodies. The Honda K20A as fitted to the Elise has shown some very nice gains in torque and HP. Is there nothing availiable for the Toyota?
 

·
shay2nak
Joined
·
25,171 Posts
Stan said:
Sorta looks like the torquey Vettes need a downshift from 6th to pass folks rapidly.
6th gear is most always overdrive to save fuel, not to accelerate. And on the Vette, if I remember correctly, 5th and 6th gears top out at the same speed. So I would suspect that most cars would require at least 5th gear for some scoot.
 
1 - 16 of 16 Posts
Top